Reserve valve mechanism



Dec. 31, 1968 R E. ROBERTS RESERVE VALVE MECHANISII Filed Nov. 14. 1966 7! 18 56 a? 56 w Z4 M if as w i i fvvsurae. Rose-'27 E. Rosa-21's flrraeusvs.

United States Patent 3,419,042 RESERVE VALVE MECHANISM Robert E. Roberts, Torrance, Califi, assignor to Sports Industries, Inc., Gardena, Calif., a corporation of California Filed Nov. 14, 1966, Ser. No. 594,224 6 Claims. (Cl. 137-613) This invention relates to self-contained breathing apparatus for use under water, in mephitic or rarefied atmospheres.

In order to allow safe return to a base where breathable gases are ambient, the user of self-contained breathing apparatus must start back when there is yet a supply of breathable gases in his tank adequate for the return trip. Known scuba equipment utilizes a spring pressed closure that actually shuts off the flow of breathable gases when the tank pressure drops to a value corresponding to the spring pressure. Thereupon, the diver operates a manual override to retract the closure, and the How of breathable gases is re-established. However the diver now knows that the tank supply is about exhausted, and he begins his ascent.

The spring force is ordinarily set so as to allow a safe ascent from a certain substantial depth. However, more time may be required in the case of cave explorations. More time may be required if the diver is required to decompress at successive levels. The obvious solution is to use a snificiently strong closure spring whereby the diver is compelled to open the reserve when there is a very substantial supply remaining. But this may be quite uneconomical for ordinary shallow dives. Reserve requirements may also be variable where breathing apparatus is used in mephitic or rarefied atmospheres.

Accordingly, the primary object of this invention is to provide a reserve valve that can be preset to determine one of a number of pressures at which the reserve valve will close.

Another object of this invention is to provide a device of this character that is essentially simple in construction, and easily operated as by any coin, screwdriver or other tool.

Another object of this invention is to provide an adapter unit that can be installed in existing reserve devices whereby the reserve device is converted for selective reserve values.

This invention possesses many other advantages, and has other objects which may be made more clearly apparent from a consideration of one embodiment of the invention. For this purpose, there is shown a form in the drawings accompanying and forming a part of the present specification, and which drawings are true scale. This form will now be described in detail, illustrating the general principles of the invention; but it is to be understood that this detailed description is not to be taken in a limiting sense, since the scope of this invention is best defined by the appended claims.

Referring to the drawings:

FIGURE 1 is a sectional view of a reserve valve incorporating the present invention, a fragmentary portion of the supply tank also being shown;

FIG. 2 is an enlarged sectional view showing a portion of the apparatus of FIG. 1 but with the parts in reserve closed position;

FIG. 3 is elevational view, a portion of the apparatus being broken away and shown in section, the apparatus being in manual override position; and

FIG. 4 is a pictorial view of the parts providing adjustment of the spring force.

In FIG. 1 there is shown a tank containing a supply of breathable gases. The tank has an internally screw- 3,419,042 Patented Dec. 31, 1968 threaded neck 12 adapted to receive an externally threaded fitting 14 of a valve body 16. A mask, mouthpiece or other structure is connected to the valve body 16 by the aid of a conventional yoke structure (not shown). This yoke structure cooperates with a projection 18 located on that side of the body 16 opposite the fitting 14. This projection 18 provides a lateral .outlet opening 20 surrounded by an O-ring 22.

Handles 24 and 26 are mounted upon oppositely extending lateral projections or stems 28 and 30 of the valve body 16. In a manner hereinafter to be described, the handle 24 operates an override for the reserve valve mechanism. The handle 26, in a manner hereinafter to be described, operates the shutotf valve for the tank 10.

The stem 30 has a stepped recess 32 in the bottom of which a valve seat 34 is formed. Gas from the tank 10 is conducted to the valve seat 34 via a passage 36. A threaded closure 38 is movable to open and close the port 34 and thus allow or prevent communication between the valve chamber 32 and the tank 10.

A valve actuator 40 is journaled in a hollow closure screw 42 attached to the end of the stem 30. The actuator 40 has a cross slot at its inner end cooperable with a key or fiat 44 formed at the outer end of the valve closure 38. The actuator 40 has a non-circular stem extending rearwardly and outwardly of the screw 42 which is connected to the handle 26. The screw 42 is sealed to the end of the stem 30, as by an O-ring 46. The actuator 40 carries an O-ring 48 that seals the internal bore of the screw 42. A spring 50 urges the handle 26 against the end of the screw 42 to impose some functional restraint against angular movement of the actuator 40. The spring is accommodated in a recess 52 of the handle 26 and its outer end bears against a cap 54 attached to the projecting end of the actuator 40.

Breathable gases, after passing into the valve chamber 32, are conducted to the bottom of an elongate valve chamber 56 that extends generally axially of the projection 18. The chamber 56 extends inwardly beyond the center line of the stems 28 and 30. In the bottom of the recess 56 a valve seat 58 is formed. A slanting bore 60 establishes communication between the chamber 32 and the chamber 56 via the valve seat 58. A reserve valve closure 62, of hexagonal or other suitable non-circular form to provide clearance with the walls of the chamber 56, is slidably movable in the chamber 56. The closure 62 carries a washer 64 at its lower end that cooperates with the seat 58. The closure 62 is urged downwardly to engage the seat 58 by the aid of a coiled compress-spring 66. The lower end of the spring fits about a cylindrical emhossment 68 formed on the upper end of the closure 62. The upper end of the spring surrounds a cylindrical emhossment 70 formed at the inner end of the spring mounting member 72 (see FIG. 4). The spring mounting member 72 is held in the recess 56 by the aid of a hollow screw 74 fastened to the end of the projection 18.

In a well-understood manner, if the pressure in the chamber 56 is less than the pressure of the supply by an amount exceeding the equivalent pressure exerted by the spring 66, then the closure 62 will be moved off its seat until pressure in the chamber 56 is increased. The pressure in the chamber 56 drops ordinarily in response to the consumption of breathable gases by the diver or user. If the pressure in the tank 10 drops below the equivalent pressure exerted by the spring 66, then the closure 62 will seat and remain seated. The interruption of flow of breathable gases is, of course, noticed by the diver and he is aware of the fact that his supply is almost exhausted. In order to restore flow the diver or user manipulates the handle 24.

The handle 24 operates an actuator that is journaled in a bore 82 of the laterally extending stem 28. The inner end of the actuator 80 has an eccentric pin 84 that projects into a lateral slot 86 of the reserve closure 62. By moving the actuator 8-0, the eccentric pin 84 is caused to engage the top of the slot 86 as hown in FIG. 3, and thus to lift the closure 62 from the seat 58. The diver then begins his ascent.

The recess 82 is sealed by a hollow screw 88 forming an outer continuation of the bore 82. O-rings 90 and 92 provide seals for preventing escape of gas through the stem 28. The actuator 80 has an extension 94 of noncircular configuration that is coupled to the handle 24. A spring 96, similar to the spring 50, engages a cap 98 at the end of the extension 94 and frictionally urges the handle 24 against the end of the screw 88. A detent 100 determines alternate stable positions of the reserve handle 24 corresponding to open and closed. The detent 100 is accommodated in a cylindrical recess 102. A spring 104 urges the detent 100 outwardly. Opposite the detent 100 is an arcuate surface of the handle 24. Formed in the arcuate surface are two notches in which the detent 100 may be fitted corresponding to the two handle positions. Thus a positive force is required in order to move the reserve handle 24 from the normal position of FIG. 1 to the override position of FIG. 3 and vice versa for obvious safety purposes.

Force exerted by the reserve valve spring 66 and hence the pressure at which the closure 62 remains seated is determined by the axial position of the spring mounting member 72. The spring mounting member 72 may be moved inwardly or outwardly. For this purpose, the spring mounting member 72 has diametrically disposed cam lobes 106 and 108 (FIG. 4) on the upper surface of a cylindrical stop flange 110 engaged by the spring 66. The cam lobes 106 and 108 are substantially of V-shape configuration. These cam lobes cooperate with two pairs of cam slots 112-114 and 116-118 formed at the inner end of the hollow screw 74. The slots 112 and 114 are located diametrically and the slots 116 and 118 are also located diametrically but in angularly spaced relationship to the cam slots 112 and 114. The slots 112 and 114 are relatively deep and thus allow the spring mounting member 72 to move outwardly to a maximum extent thus to reduce the tension in the spring 66. The slots 116 and 118 are relatively shallow and, accordingly, when the lobes 106 and 108 are positioned so as to enter these slots, the spring mounting member 72 is moved forwardly and the spring 66 is consequently tensioned to a larger degree. The cam slots 112-114, 116-118 are angled to determine stable angular positions of the spring mounting member 72. Thus until the member 72 is forcibly turned, it stays in place.

The spring mounting member 72 has a stern portion 120 journaled in the cylindrical bore 122 of the screws 74. The stem carries an O-ring 124 that prevents leakage past the stem. The screw 74 is sealed to the projection 120 by the aid of an O-ring 126. The upper end of the stem has a cross slot 128 that may be engaged by a coin, screwdriver or other tool for imparting angular movement to the spring mounting member 7 2. Suitable legends may be printed on the end of the screw 74 to indicate high or low reserve.

Before the diver descends, he moves the reserve handle 24 to the retracted position of FIG. 1 and selects the degree of reserve that he wishes by rotation of the spring mounting member 72.

By providing additional pairs of cam recesses, additional reserve selections can be determined.

The inventor claims:

1. In self-contained breathing apparatus a reserve valve mechanism having an inlet cooperable with a supply tank, and having an outlet; means operative upon a reduction in pressure of the supply to interpose an operative restriction between said inlet and said outlet to provide a reserve signal to the user of the near exhaust of breathable gases; manual override means for removing said restriction and to place the inlet and the outlet in substantially unrestricted communication whereby the remainder of breathable gases in said supply tank is freely available to the user; and means for adjusting the value of the pressure reduction at which said restriction becomes operative whereby the user preselects the quantity of breathable gases in said supply tank following the reserve signal.

2. The combination as set forth in claim 1 in which said means operative to interpose an operative restriction comprises a valve closure cooperable with a seat and a compression spring urging the valve to closed position.

3. The combination as set forth in claim 2 in which said adjusting means includes an abutment anchoring one end of said spring, and means for moving the abutment toward or away from said seat to change the tension of said spring.

4. In self-contained breathing apparatus: a valve body; means forming a valve chamber opening exteriorly of the body; means forming a valve seat at the inner end of said valve chamber; said valve body having passage means for conducting breathable gases from a supply tank to said valve seat; means forming an outlet extending laterally of said valve chamber for delivery to the user of the breathing apparatus; a valve member guided in said valve chamber for movement toward and away from said seat for closing and opening communication between said passage means and said valve chamber; a compression spring having an inner end engaging said valve member; a spring mounting member engaged by the outer end of said spring; a hollow closure attached to said body at said opening of said valve chamber, and having a cylindrical bore; said spring mounting member having a substantially cylindrical extension guided in said bore and mounted thereby for angular movement about the common axis of said bore and extension; and cam means operative between said closure and said spring mounting member for changing the axial position of said spring mounting member in accordance with its angular position thereby to determine one of a number of preselected spring pressures on said valve member and thereby the pressure at which the source is incapable of moving said valve member; and manual override means for positively retracting said valve member.

5. The combination as set forth in claim 4 in which said cam means includes a cam lobe formed on said spring mounting member and number of seat forming surfaces on the inner end of said closure located at different longitudinal positions.

6. The combination as set forth in claim 4 in which said spring mounting member has a pair of diametrically disposed angular cam lobes, said closure having a first pair of seat forming notches at its inner end cooperable with said cam lobes to determine one longitudinal position of said spring mounting member, said closure having a second pair of seat forming notches at its inner end angularly spaced from said first pair of seat forming notches and cooperable with said cam lobes to determine another longitudinal position of said spring mounting member.

References Cited UNITED STATES PATENTS 3,024,803 3/1962 Beremand 137-613 X NATHAN L. MINTZ, Primary Examiner. 

1. IN SELF-CONTAINED BREATHING APPARATUS A RESERVE VALVE MECHANISM HAVING AN INLET COOPERABLE WITH A SUPPLY TANK, AND HAVING AN OUTLET; MEANS OPERATIVE UPON A REDUCTION IN PRESSURE OF THE SUPPLY TO INTERPOSE AN OPERATIVE RESTRICTION BETWEEN SAID INLET AND SAID OUTLET TO PROVIDE A RESERVE SIGNAL TO THE USER OF THE NEAR EXHAUST OF BREATHABLE GASES; MANUAL OVERRIDE MEANS FOR REMOVING SAID RESTRICTION AND TO PLACE THE INLET AND THE OUTLET IN SUBSTANTIALLY UNRERSTRICTED COMMUNICATION WHEREBY THE REMAINDER OF BREATHABLE GASES IN SAID SUPPLY TANK IS FREELY AVAILABLE TO THE USER; AND MEANS FOR ADJUSTING THE VALUE OF THE PRESSURE REDUCTION AT WHICH SAID RESTRICTION BECOMES OPERATIVE WHEREBY THE USER PRESELECTS THE QUANTITY OF BREATHABLE GASES IN SAID SUPPLY TANK FOLLOWING THE RESERVE SIGNAL. 